下载网络资源方法-java版

有时需要用到程序下载某个网络资源，比如图片，word文档，pdf，web页面等，网上也有很多，这里用到重写一下，方便热后直接使用，懒人计划....  : )

直接看看方法

public class Funs {public static String downloadNetFile(String refFileURL, String refSavePath, String refFileType){/* parameters: * 1,refFileURL: is a url of file which exists in international (www)net;  * 2,refSavePath: is path of file which success download and save in it, eg.: e:\path; * 3,refFileType: is a type of file, eg.: gif or jpg or png or htm or html or ppt or doc or... *  * return type:  * data type: String, only return a file name or a empty String, not include path * */String retValue = "";if(null == refFileURL || refFileURL.trim().isEmpty() || null == refSavePath || refSavePath.trim().isEmpty()|| null == refFileType || refFileType.trim().isEmpty()){retValue = "";}else{//default value of fileNameString fileName = "down_" + new SimpleDateFormat("yyyyMMdd_HHmmssSSS").format(Calendar.getInstance().getTime());String fileType = refFileType.trim();if(!fileType.startsWith(".")){fileType = "." + fileType;}fileName = fileName + fileType;String savePath = refSavePath.trim();if(!savePath.endsWith("\\")){savePath = savePath + "\\";}String saveDownFile = savePath + fileName; String fileURL = refFileURL.trim();try {//create URL object URL fileUrl = new URL(fileURL);//connect to net URL resource and create HttpURLConnection object               HttpURLConnection connection = (HttpURLConnection) fileUrl.openConnection();              //also can to use BufferedInputStream and BufferedOutputStream object            //get net source input stream            DataInputStream ins = new DataInputStream(connection.getInputStream());             //rewrite the new file content if exists same file            DataOutputStream out = new DataOutputStream(new FileOutputStream(saveDownFile,false));             byte[] buffer = new byte[4096];              int count = 0;              while ((count = ins.read(buffer)) > 0){                  out.write(buffer, 0, count);              }              out.close(); //close dataInputStream and release resource            ins.close(); //close dataOutputStream and release resource             connection.disconnect(); //close net download stream            retValue = fileName;} catch (Exception e) {retValue = "";}savePath = null;fileURL = null;fileType = null;}return retValue;}}